Variable Speed Control For A 220v Fan?

[jyl]

I’m installing an upblast exhaust fan on my house, as part of a vent hood for my kitchen. Haven’t chosen the exact model yet but it will probably be a 220v model drawing max 6A from CaptiveAire, who make the hood.

CaptiveAire sells a fancy electronic controller for $800 that requires an 30” x 40” x 12” electrical cabinet It has the bells and whistles for a commercial install, including automatic temperature control of the fan and fire suppression control. They said this controller is overkill for a house, and suggested I just have my electrician install a simple switch.

So, what switch should I get? I want a variable speed controller, so I can run the fan at lower or higher speed. Ideally it will be small enough that I can mount it in the wall by the range.

Anyone know a suitable part?

If the 220v thing is a problem, I can use a 110v fan. I’d rather use 220v to reduce the wire gauge though. There will be about 30’ of wire from the subpanel in the basement to the fan on the exterior wall of the house, the switch will be on that run.

[jyl]

Will something like this work?

https://www.grainger.com/mobile/product/FANTECH-Speed-Control-15W824?breadcrumbCatId=3193

[908/930]

Really do not think you need 220v, unless you are going 2hp. The best way to get variable speed is with a variable frequency drive, the variable transformer similar to that Fantec will work but the motor will likely Hum at lower speed, it is reducing voltage vs changing the frequency. Some VFD are NEMA 4 so sort of have their own enclosure but still need space around them for cooling, and with most you can wire the on switch and potentiometer to a remote location. Look up 120v vfd will need to make sure the fan motor will work properly with one.

[1990C4S]

Amazon has a wide variety of VFD's. You can wire an input for temp control if you want that too.

Automationdirect is another place to shop: https://www.automationdirect.com/adc/shopping/catalog/drives_-a-_soft_starters/ac_variable_frequency_drives_(vfd)#Horsepower_Rati ng_ms=%222hp%22&start=0&Nominal_Output_Voltage_ms=%22230%20VAC%22

[908/930]

6A at 220v so about 3/4hp, that is a big fan motor, where are you getting the make up air from? Cutting a 10" hole somewhere?

[jyl]

Originally Posted by 908/930

6A at 220v so about 3/4hp, that is a big fan motor, where are you getting the make up air from? Cutting a 10" hole somewhere?

Either floor register with duct through basement or register in the cosmetic surround that will fill the space between hood and ceiling. Haven’t figured it out yet :-)

[jyl]

Hmm, the wife is not going to be pleased at having to use something that looks like a lab instrument to turn on her hood fan . . . the “user interface” needs to be a knob or a switch or a few buttons . . .

[908/930]

Is there a reason you want so much extraction power? I think that would be capable of about 2000CFM, try turning the heat down a little. That is a lot of air to replace, hope you do not have a fireplace.

With the VFD's you would run a remote on off switch and a potentiometer, can use standard rocker switch, and keep the controller close to the motor. Is there anywhere you can hear one of the fans you are looking at running?

Could you run two smaller fans branched through a y? Run one for low and both for high?

[wilnj]

Originally Posted by 908/930

Is there a reason you want so much extraction power? I think that would be capable of about 2000CFM, try turning the heat down a little. That is a lot of air to replace, hope you do not have a fireplace.

With the VFD's you would run a remote on off switch and a potentiometer, can use standard rocker switch, and keep the controller close to the motor. Is there anywhere you can hear one of the fans you are looking at running?

Could you run two smaller fans branched through a y? Run one for low and both for high?

If this is even close, I think you’ve go too much fan. The commercial kitchen I just finished has 4,000 cfm of exhaust (CaptiveAire as well). That kitchen has 7 pieces of equipment; a convection oven, 2 fryers, 6 burner range with oven, flat top, grille and a salamander.

[LWJ]

I think too much suction as well. I have a 120v vent-a-hood. It pulls too much. Sounds like a jet.

It does look cool and can clear out smokey mistakes in a nanosecond.

[jyl]

I EDITED THIS WITH MORE INFO

I have the CaptiveAire specs at the office. CaptiveAire direct drive upblast, model DU50HFA, 1000 CFM, ESP 0.800, RPM 1399, HP 0.50, 230v, FLA 3.5, discharge velocity 380 FPM, weight 81 lb, sones 13.9. It will be wall mounted on the exterior of the house.

My local restaurant supply place helped me spec it.

The hood is 5’ wide but only 33” deep and “low profile” so it won’t capture as well as if it were deeper and full height. The leading edge of the hood is going to be about 72" above the floor and about 40" above the range, and vertically only about 3" further from the wall than the range. Thus when hot greasy air rises and spreads from my wok on the front burner, much of the plume will miss the hood, unless there's enough airflow to pull it in.

Pulling through 12” duct, two elbows and 6’ horizontal run. Drawing of hood below:

https://www.captiveaire.com/CATALOGCONTENT/HOODS/BD2/SubmittalDrawing.asp?img=drawings/bd2%20iso

The range is 36” and 130,000 BTU and I told the place I wanted the ability to switch to a larger range or add a second piece of cooking equipment later. I have a fantasy of someday adding a wok range next to the main range.

[rusnak]

Just add a second hood, and duct it into the first one with a single 110v reasonably sized fan with a wall mounted on/off switch. That's what I did and it works perfectly. I added an LED light in the hood to light the area underneath.

[jyl]

There’s no hood now - it was an OTR microwave :-)

[rusnak]

The two hoods are ducted into one roof fan. The fan is a sensible size, just enough to extract excessive cooking heat. It's not like a "whole house" fan. Those things sound like a turboprop on take-off.

[jyl]

rusnak, no grease filter?

[rusnak]

^ That area has no stove. It's above a stack of ovens and a worktop freezer. A grease filter can be added in the event that a stove is moved there.

[jyl]

here's what it is supposed to look like. The duct has a 90 elbow, goes through the wall into the stairwell, then a 90 elbow and goes out to the exterior wall. There is lots of clearance for the ducting, and I was thinking about having the elbows be larger diameter arcs for better airflow.

WTF I cannot post images - they don't show up.

[1990C4S]

Originally Posted by jyl

Hmm, the wife is not going to be pleased at having to use something that looks like a lab instrument to turn on her hood fan . . . the “user interface” needs to be a knob or a switch or a few buttons . . .

You would wire a rheostat back to the controller. 0-100% speed control.

[908/930]

The larger rad elbow should also help with air flow noise. There is a minimum amount these motors need to spin 300-400rpm, they need airflow for cooling. In another post I think it was look171 mentioned a inline muffler to help keep fan noise down, pretty good option if you have the room.

[billybek]

Originally Posted by 1990C4S

You would wire a rheostat back to the controller. 0-100% speed control.

This. A VSD/VFD and in the space via low voltage wire an on/off for a binary input to start the fan and a rheostat to control speed. Very simple.

Speed drive would have to be programmed as mentioned for minimum fan speed.